Environment

Pumas in need of space

Mountain lions in the Santa Monicas are trapped on an island of habitat.

FROM an urban puma’s perspective, the news of late from greater Los Angeles has been mixed. On the positive front, a small population of pumas is surviving in the relatively compact confines of the Santa Monica Mountains in California, where deer are plentiful and the mountain lions have found mates and reproduced. One healthy male puma has made Griffith Park, in the range’s eastern reaches, his domain and dinette for nearly two years.

On the flip side, a puma (also called cougar) that would have brought new genetic material managed to cross the 101 Freeway last October but encountered a 3m retaining wall and was struck and killed by a motorist. In the latest sobering revelation, the National Park Service said that three mountain lion kittens born in the Santa Monica Mountains recently appear to be the result of inbreeding.

Taken together, scientists say, these developments underscore the need for easing the passage of wildlife between open lands now bisected by the 101 in Agoura Hills, about 48km north-west of downtown Los Angeles.

Mountain lions in the Santa Monicas are trapped on an island of habitat, constrained by freeways, the Pacific Ocean and the agricultural fields of Oxnard. The inbreeding is further evidence that male lions need more room to roam to expand their mating options, experts say.

“This is the third of six kitten litters we’ve studied where we’ve documented first-order inbreeding, in which a father mates with his offspring,” said Seth Riley, an urban wildlife expert at the Santa Monica Mountains National Recreation Area, a unit of the National Park Service. Riley and his team have studied mountain lions in the area for more than a decade.

Preliminary paternity results from the University of California, Los Angeles’ Robert Wayne Lab indicate that Puma 12, known as P-12, is the father of the three new kittens and the father of their mother, P-19. The kittens – one male and two females known as P-32, P-33 and P-34 – were born in the Malibu Springs area; biologists have attached ear tags to the youngsters. Over multiple generations, inbreeding leads to a loss of genetic diversity and can result in low sperm counts, heart problems and lower resistance to disease.

Riley’s studies have shown that the top causes of death among the Santa Monica Mountains’ puma population are conflicts with other lions, exposure to rat poisons and encounters with moving vehicles.

The California Department of Transportation has twice sought federal funding for a US$10mil (RM32mil) tunnel crossing near the Liberty Canyon Road exit. The area is part of a critical wildlife corridor that connects the Santa Susana Mountains and Simi Hills to the Santa Monica Mountains.

Riley and others working with the department recently proposed what they consider a superior option: a landscaped crossing over the freeway. Such overpasses have been successful in Canada and Europe and are starting to be used in the Western United States.

“I’m arguing pretty aggressively for an overpass,” said Joseph T. Edmiston, executive director of the Santa Monica Mountains Conservancy, which owns much of the land near the proposed crossing. “It would be more inviting for the animals.”

A robust wildlife crossing “is the key to genetic health in the Santa Monica Mountains,” said Clark Stevens, executive officer of the Resource Conservation District of the Santa Monica Mountains. As high a priority as it is, Stevens said, “it will take a lot of separate money cobbled together” by a public-private partnership to build. – Los Angeles Times/McClatchy Tribune Information Services